VITESSE
SEMICONDUCTOR CORPORATION
Preliminary Data Sheet
VSC7924
SONET/SDH 2.5Gb/s Laser Diode Driver
Input Termination Schemes
Figure 1: Input Structure
OV (GND)
DIN X
11.440k0Ω
VREF X
TERM X
12pF
3Ω
44.330k0Ω
114.40k0Ω
+
-
44.330k0Ω
• Nominal VREF = -1.3V
• 1400, 4300 Ohm Resistor
on die, nominal values
Nominal VREF = 1.3V
1.4kΩ, 4.3kΩ resistor on die, nominal values
GND -5.2V (VSS)
SOURCE
Figure 2: Single-Ended AC Coupled
GND
0.1µF
DIN
X
+
50Ω
TERM or VREF
X
-
-2V
0.1µF
GND
VSS
Figure 3: Single Ended AC Coupled with Offset Adjust
GND
SOURCE
0.1µf DIN
X
+
50Ω
VREF
-
X
GND
2k0Ω00
4.330k0Ω
3 VSS
X
TERM
0.1µf
VSS
GND
G52156-0, Rev 3.0
05/01/01
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Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: prodinfo@vitesse.com
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